Ln0.4Sr0.6Co0.8Fe0.2O3-δ(Ln = La, Pr, Nd, Sm, Gd)for the electrode in solid oxide fuel cells

摘要

Perovskite-type oxides of Ln0.4Sr0.6Co0.8Fe0.2O3-δ(Ln = La, Pr,Nd,Sm, Gd) have been prepared by the solidstate reaction of corresponding oxides. The electricalconductivity of the sintered samples showedsemiconductor-like behavior at a lower temperature andmetallic behavior at a higher temperature.Nd0.4Sr0.6Co0.8Fe0.2O3-δexhibited the highestconductivity in Ln0.4Sr0.6Co0.8Fe0.2O3-δin thetemperature range of 25- 1000°C. The reactivity testof these oxides with 8 mol% Y2O3 doped zirconia (8YSZ)was carried out between 800 and 1000°C for 96 h in air.The perovskite oxides reacted with 8YSZ to produceSrZrO3 at 900°C and no reaction product was observedat 800°C. The cathodic polarization of these oxideelectrodes sputtered on the 8YSZ tablet was studied at600-800°C in air. Nd0.4Sr0.6Co0.8Fe0.2O3-δshowed thebest catalytic activity for oxygen reduction. Theseperovskite oxides showed no degradation of the electrodeperformance by annealing between 600 and 800°C.